In a printing system such as a rotary press, a device for laminating or coating a sheet material, or a device for the production of a corrugated sheet for use in corrugated cardboard, there is adopted a sheet rewinder which unwinds a sheet of paper, for example, as a raw material for the aforementioned device from a sheet roll keeping the sheet in a rolled form thereon and feeds it to the aforementioned device.
In the rewinder of the kind described above, at least one sheet roll is mounted in place as a standby besides the sheet roll currently in use for the purpose of improving the operational efficiency of the rewinder. As the sheet unwound from the sheet roll to undergo the desired treatment is exhausted, the other sheet roll standing by is set rotating to pay off a fresh sheet. Generally, it has been customary to stop the rotation of the old sheet roll as the supply of the sheet from this sheet roll approaches its end, sever the sheet from the sheet roll by inserting a cut near the trailing end of the sheet, and join the cut end of the former sheet to the leading end of the sheet unwound from the new sheet roll. A splicer used for joining the trailing end of the sheet from the old sheet roll to the leading end of the sheet from the new sheet roll without interrupting the operation of the printing system or the corrugator or some other sheet-fabricating device has been known to the art. The conventional sheet splicer necessitates provision of accumulator rolls (dancer rolls). It is so complicated in construction that the operator is compelled to guide the sheet in a zigzag path through rolls while passing the leading end of a sheet paid off a new sheet roll. This work requires much time and labor.